Quinolone type structures are known for their antibacterial properties, and several quinolone antibiotics (e.g. norfloxacin and ciprofloxacin) are on the market. Quinolone antibiotics may be considered as having two main structural components, the quinolone nucleus and side chains covalently bound to that nucleus. The composition of the side chain attached to the quinolone nucleus controls many of the properties of the antibiotic. Properties such as the antibiotic's potency and side effects may be strongly influenced by the structure of the side chain.
The manufacture of the side chain is a critical component in the manufacture of the quinolone antibiotic. With some quinolone antibiotics the side chain can be manufactured independently from the quinolone nucleus. This invention discloses a new method of producing a purified intermediate that can then be processed into a side chain intermediate which can be attached to a quinolone nucleus in order to produce a useful antibiotic.
Purification steps are very important in the manufacturing of pharmaceutical drugs. Every step in the manufacture of a drug requires expense in the form of operators, equipment and protocols that ensure the proper product is created. The manufacturing process and conditions must comply with both good manufacturing practices and with numerous regulations. Here we disclose a novel and useful purification step in the manufacture of a quinolone antibiotic diamine pyrrolidine side chain intermediate for a quinolone antibiotic that allows production of the antibiotic in significantly greater yields and at lower costs than was previously possible.